Aspects of this disclosure are directed to motor housings, and in particular motor housings for electric appliances such as blenders.
Electric appliances have become commonplace in a variety of settings, such as home kitchens, as well as commercial uses, such as restaurants, cafeterias, coffee shops, and bars in a variety of settings. One category of electric appliance includes mixers and various forms of blenders. At their most basic, blenders include a water-tight or sealed container atop a lower power unit. A blender typically utilizes an electric (or otherwise powered) motor to drive a vertical drive shaft, where the drive shaft turns a blade or mixing element located within the blender container. A substantial amount of revolutions per minute (RPM) and corresponding rotational blade force are then used to mix, agitate, or “blend” the contents of the container.
In the process of blending, the lower power unit uses the motor to convert electricity from a wall source (usually alternating current) or battery (usually direct current) into rotational force through the shaft. The drive shaft can then turn a blending blade in the container, above. During blending, the motor in the lower power unit inevitably creates undesirable heat. If the temperature of a motor or other components become elevated, parts, connections, and other blender components can weaken, melt, or otherwise break. In order to avoid such problems, a blender typically also includes a cooling fan coaxially mounted to the drive shaft driven by the motor. Typically, the cooling fan is mounted below the motor to be cooled, such that the fan blades of the cooling fan can expel hot air from the motor directly to the surrounding environment.
Blenders are very often stored and then used in open areas, such as a countertop within a kitchen or an open bar, café, or coffee shop. As such, a very common complaint or irritation is that blenders create a substantial quantity of wide-band sound when in use, otherwise considered to be noise. In a typical blender, noise (conventionally measured in the base-10 logarithmic units of decibels acoustic [dBA]) originates from a variety of components during a blending process, but most notable are the actual crushing or blending of a food or beverage product in the container and the noise created by the motor and cooling fan and electric motor apparatus, the latter which forms the primary focus of this application. Sufficient cooling being considered a necessity for safe operation, the motor and cooling fan portion of blenders have been well-established for many years, and known configurations include the motor mounted at or near the middle of the roughly cylindrical base power unit, with the cooling fan located below the motor (and therefore the cooling fan being located closer to the surface on which the blender is placed). More recently, a desire has arisen to improve the quietness of blenders during blending (i.e., reduce the noise emitted). Existing methods for quieting blenders have generally had limited success.